Optimization Of Array Configuration Research Articles

Hybrid-index-based array configuration optimization for Michelson interferometric imaging

Array configuration design is a critical issue for a high quality of the snapshot point spread function (PSF) and restored image in Michelson imaging interferometer. In classic design, the optimized configurations usually address the few specifications and single objective, which is unable to balance the requirements of both non-redundancy and sampling distribution. In this paper, we formalize mathematically the composite metric to trade-off the multiple demands of observation, and propose the hybrid-index-based array layout optimization strategy. The simulation results demonstrate that, in comparison with the typical distribution, the optimized array using the proposed optimization framework enables the acquisition of more comprehensive spectrum information while utilizing an equal number of apertures, providing superior imaging quality in different observation situations. Furthermore, the designed optimized array masks and the compared conventional array masks were fabricated and used for our experimental validation, further verifying the feasibility of this strategy. This array configuration optimization framework may not only find applications to Michelson interferometric imaging, but also provide a positive impact on all u-v sampling-based imaging modes, including radio interferometry, magnetic resonance imaging, and photonic integrated interferometric imaging.

Target Localization Based on High Resolution Mode of MIMO Radar with Widely Separated Antennas

Coherent processing of multiple-input multiple-output (MIMO) radar with widely separated antennas has high resolution capability, but it also brings ambiguity in target localization. In view of the ambiguity problem, different from other signal processing sub-directions such as array configuration optimization or continuity of phase in space/time, this paper analyzes it from the information level, that is, the tracking method is adopted. First, by using the state equation and measurement equation, the echo data of multiple coherent processing intervals (CPI) are collected to improve the target localization accuracy as much as possible. Second, the non-coherent joint probability data association filter (JPDAF) is used to achieve stable tracking of spatial cross targets without ambiguity measurements. Third, based on the tracking results of the non-coherent JPDAF, the ambiguity of coherent measurement is resolved, that is, the coherent JPDAF is realized. By means of non-coherent and coherent alternating JPDAF (NCCAF) algorithms, high accuracy localization of multiple targets is achieved. Finally, numerical simulations are carried out to validate the effectiveness of the proposed NCCAF algorithm.

Unmanned Aerial Vehicles Swarm-Based Distributed Phased Arrays for Grating Lobe Mitigation and Collision Avoidance

Distributed phased arrays based on unmanned aerial vehicle (UAV) swarm with small antenna elements on each micro-UAV are expected to achieve much better performance than the traditional phased arrays due to a large amount of swarm mobile individuals and deployment flexibility. To avoid the possible collisions of the flying UAVs, a large separation distance between UAVs is required, but grating lobes can appear when the array element spacing is larger than one-half wavelength. To solve this issue, array antennas with aperiodic element placement are normally used to mitigate the grating lobes, while suffering from a high collision risk for UAVs due to the reduced array element separation in the aperiodic array. This paper proposes a novel 3-D aperiodic array design by adding an additional degree of freedom in the optimization of array configuration. The sidelobe levels can be largely reduced from the planar periodic arrays. In addition, the collision risk for UAVs represented by the minimum separation distance between array elements can be largely decreased from the planar aperiodic arrays. This work provides a feasible strategy for the design and optimization of the UAV swarm-based phased arrays for practical applications.

Damage localization in pressure vessel using guided wave-based techniques: Optimizing the sensor array configuration to mitigate nozzle effects

Ultrasonic guided waves are desirable technologies for damage monitoring in large structures such as pipes and pressure vessels since they could propagate over a long distance with low attenuation. However, due to the complex scattering of guided waves, it is a great challenge to extract the damage information when using guided wave-based techniques to monitor the pressure vessels equipped with accessories. As an attempt, we investigated the interactive behavior between guided waves and pressure vessel nozzles. Ensemble empirical mode decomposition, fast Fourier transform and ellipse-based damage localization algorithm are adopted to perform the signal processing and damage localization analysis, respectively. A sensor array configuration optimization method is presented to mitigate the nozzle effects on the propagation of guided waves. The optimal number of sensors is determined experimentally, and the sensor array placement is optimized by a Particle Swarm Optimization algorithm. The accurate experimental damage localization results in the pressure vessel and curved plate indicate the effectiveness of our methods.

Array configuration optimization of first-order steerable differential arrays with minimum number of microphones.

The first-order steerable differential arrays (FOSDAs), which have found a variety of applications in speech and audio processing, are usually designed by construction of two orthogonal dipoles using four microphones. Actually, however, three microphones are enough to construct a FOSDA by forming two dipoles with a shared microphone, which is the scheme with the minimum number of microphones and, hence, the most cost-effective. This paper studies the design and analysis of such three-element FOSDAs by using a least-squares method. In particular, the effect of the array configuration on the three-element FOSDA is studied, and optimum array configurations under different steering angle ranges are derived in terms of both beampattern fitting quality and white noise gain. It also reveals that care should be taken to avoid a conservative setting of the steering angle range in order to achieve superior design of the three-element FOSDA.

Embryonic array configuration optimization method based on reliability and hardware consumption

Embryonic Array (EA) with different configuration methods will directly affect its reliability and hardware consumption. At present, EA configuration design is lack of quantitative analysis method. In order to reasonably optimize EA configuration design, an EA configuration optimization design method is proposed, which is based on the constraints of EA hardware consumption and reliability. Through the analysis of EA working process and composition, quantitative analysis of EA reliability and hardware consumption are completed. Based on the constraints of EA hardware consumption and reliability, the mathematical model of EA configuration optimization design is established, which transfers EA configuration optimization design into an integer nonlinear programming model problem. According to the difference of the fitness value of individual waiting for mutation in population, adaptive mutation operator and crossover operator are selected, and a novel Modified Adaptive Differential Evolution (MADE) algorithm is proposed, which is used to solve EA configuration optimization design problem. Simulation experiments and analysis indicate that the MADE is able to effectively improve the speed, accuracy and stability of algorithm. Moreover, the proposed EA configuration optimization design method can select the most reasonable EA configuration design, and play an important guiding role in EA optimization design.

Abstract 3204: Transducer array configuration optimization for treatment of pancreatic cancer using Tumor Treating Fields (TTFields)

Abstract Introduction: TTFields is an antimitotic cancer treatment that utilizes low intensity (1-3 V/cm) alternating electric fields in the intermediate frequency (100-300 kHz) that are delivered in two orthogonal directions using 2 pairs of transducer arrays. A phase II clinical trial (PANOVA, NCT01971281) showed that TTFields in combination with chemotherapy was safe in patients with locally advanced pancreatic cancer. Preclinical studies show that the effect of TTFields is intensity-dependent with a therapeutic threshold of 1 V/cm. The field distribution within the body is known to changes with array placement. Therefore, there is a need to develop principles for personalizing array placement to optimize TTFields delivery when treating pancreatic cancer. The aim of such guidelines should be to ensure delivery of maximal field intensities to the region of disease, whilst minimizing the size of the arrays placed on the body. Minimizing array size is important to enable periodic shifting of the arrays for potentially reducing skin irritation associated with TTFields therapy, as well as potentially improving overall patient comfort. Here we present a systematic study investigating how the location and size of the arrays on the abdomen influences the field distribution. Methods: To simulate delivery of TTFields to the abdomen, we used 3 realistic computerized models (from ZMT_Zurich) of: a male (DUKE 3.0); b) , a female (ELLA 3.0); and an obese male (FATS 3.0). For each model, 6-8 different layouts utilizing combinations of arrays with either 13 or 20 disks per-array were tested. The arrays were placed over the upper 6 standard abdominopelvic, and field intensity distributions within these regions were evaluated. In order to generate TTFields, an alternating voltage at a frequency of 150 KHz was imposed on the outer surfaces of the disks of each pair of arrays. The voltage was set to deliver a current of 200 mA peak to peak per-disk (total current 2.6 A for 13-disk arrays, 4.0 A for 20-disk arrays). The simulations were performed using ZMT's Sim4Life V3.0 electro-quasi-static solver. Results: In all simulations, the large arrays generated higher field intensities than the small arrays. However, On ELLA and DUKE, the large arrays covered most of the skin around the abdomen, leaving little to no room for shifting the arrays. FATs body surface is large enough so that even when large arrays are used, there is still ample space for shifting the arrays. On DUKE and ELLA, when using small arrays, the average field intensity in the abdominopelvic region over which the arrays were placed was above the therapeutic threshold of 1 V/cm. Conclusion: This work shows that TTFields array placement can be optimized to deliver therapeutic field intensities to specific abdominopelvic regions. Tailoring the size and position of the arrays based on disease site and patient size may help to improve overall treatment outcome. Citation Format: Ariel Naveh, Ze'ev Bomzon, Ori Farber, Noa Urman, Ofir Yesharim, Eilon Kirson, Uri Weinberg. Transducer array configuration optimization for treatment of pancreatic cancer using Tumor Treating Fields (TTFields) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3204.

The Array Configuration Optimization of Phased Array Radar with ADBF in Electronic Countermeasure Environment

ADBF相控阵雷达通常采用子阵结构。子阵结构对系统性能具有显著影响，对相控阵进行最优子阵划分具有重要的理论与应用意义。该文利用多目标进化算法(MOEA)进行子阵结构优化，使系统在主瓣干扰下具有尽可能好的抗干扰及和、差波束旁瓣抑制性能。将和波束自适应方向图的旁瓣电平、系统输出SINR及差波束的旁瓣电平作为优化目标，构造了5种目标函数。给出了MOEA子阵结构的编码方法。基于Pareto秩排序的MOEA将3032的平面阵划分为64个子阵的仿真结果表明，系统的多种性能得到了提高。

Optimization of array configuration

The following article appeared as: Penner, A.R. (1987). Optimization of array configuration. Journal of the Acoustical Society of America, 82(6), 2152-2154, and may be found at: http://dx.doi.org/10.1121/1.395661.

Systematic Design of Observational Arrays

Abstract The variational data assimilation method of Bennett and McIntosh permits an assessment of the information content of observational arrays. This method relies on an approximate knowledge of the (linen) dynamics of the system, and on the instrument location, so that the efficiency arrays may be ascertained before deployment. The cumbersome trial-and-error optimization of array configuration may be circumvented by a careful study of the physics underlying the data assimilation procedure. As an example, array design criteria are developed for observing barotropic tides using tide gauges. In an open-ended channel, the variational method endeavors to synthesize the free modes of an infinite channel. Instruments should be located to facilitate the resolution of these modes. In a channel that is too small to support propagating Poincare waves. tide gaups are best deployed along open sea boundaries where the amplitude of exponentially decaying Poincare waves is largest. The maximum number of instruments c...